In the current window and door market there are two primary or main locking cylinders used to secure windows and doors in a secured or locked position. The first is the American cylinder and the second is the Profile cylinder.
As shown in FIG. 1, a prior art door locking system 10 is shown having an internal plate mount 14 and an external plate mount 18 positioned on either side of an American cylinder mortise lock 22. The American cylinder mortise lock 22 comprises a mortise receiver 24 and various internal locking components, including a bolt 26. The American cylinder mortise lock 22 is operable with an American cylinder lock 34 having an internal cam (not shown) used to selectively turn the components of mortise lock 22, and particularly bolt 26, thus locking and unlocking a door (not shown). The internal cam further prevents American cylinder 34 from freely rotating. Instead, the cam is made to contact one or more stoppers within American cylinder 34 that limit its range of rotation.
The American cylinder lock 34 is widely used in the United States as a standard cylinder lock. It is small and mounts from behind the door hardware. A flat tailpiece 38 extends from behind the mechanism of American cylinder lock 34 and extends into mortise receiver 24. When a key is inserted and turned, the internal cam causes tailpiece 38 to rotate, which subsequently turns or drives bolt 26 inside mortise lock 24. Turning the cam functions to drive bolt 26 into a door jamb (not shown), thus locking the door. The benefit of the American cylinder is that it is cost effective. In addition, because the American cylinder lock is mounted from behind the door hardware, and particularly external plate mount 18, it is protected from environmental elements that can corrode or rust its various components. As such, the life of locking mechanism 10 is extended and the durability of the locking mechanism is increased. Another benefit is that tailpiece 38 can comprise different lengths that are easily interchangeable or cut to accommodate different door thicknesses.
Referring now to FIG. 2, shown is another prior art door locking system 10. Door locking system 10 comprises an internal plate mount 40 and an external plate mount 44 positioned on either side of a Profile cylinder mortise lock 48. A Profile cylinder mortise lock 48 comprises an eyehole 52 allowing access to various internal locking components, such as a bolt (not shown). Profile cylinder mortise lock 48 is operable with a Profile cylinder 54 having a cam 56 used to selectively turn the components of mortise lock 48, and particularly the bolt, thus locking and unlocking a door. A Profile cylinder 54 is a type of locking cylinder that is primarily used in Europe, but that is also frequently used in the United States. A Profile cylinder 54 mounts by placing it through external plate mount 40 and mortise lock 48 with a screw 50 coming in edgewise, thus securing Profile cylinder 54 into place. Unlike the American cylinder illustrated in FIG. 1, Profile cylinder 54 has no tailpiece. Instead, cam 56 is built directly into Profile cylinder 54. When a key is inserted and turned, cam 56 is caused to rotate. This rotation subsequently drives the bolt into the door jamb, thus securing or locking the door.
There are several deficiencies inherently associated with the Profile-type locking assembly. The Profile cylinder is comparatively expensive compared to the cost of the American cylinder. Thus, if the locking cylinder malfunctions or breaks, the purchase of a new one will be significant as compared to other locking cylinders. In addition, the Profile cylinder mounts from the outside of the door as shown in FIG. 2, thus leaving its component parts exposed to environmental elements that can corrode the various internal components. Another disadvantage is that there is no tailpiece. Because there is no tailpiece, in order to accommodate different door thicknesses, an entire new locking cylinder must be purchased. Thus, a particular Profile locking assembly made for one door thickness may not be interchanged for use on another door thickness. And, since different manufactures offer several different door thicknesses, several different sized Profile cylinders must be manufactured and stocked. Finally, the components of the Profile door locking assembly do not fit tightly together, but comprise varying degrees of slop. Other problems not specifically recited herein will be apparent to one skilled in the art.